采用液体培养法研究了馒头柳对镉的耐性、运输过程及富集特征,结果表明:馒头柳具有较强的耐镉特性,水培营养液中镉浓度为0.2mg·L-1时,镉对柳的生长仍有促进作用;镉从根到地上部的长距离运输具有明显的韧皮部运输特征,表现为植株顶部组织镉含量显著高于底部(P〈0.05),韧皮部高于木质部(14倍);馒头柳地上部对镉有非常强的持续富集能力;地上部富集的镉占植株吸收总镉量的52%~62%,且主要集中在叶片,只要秋季清除地表落叶,即可达到清除土壤镉的目的;因此,馒头柳适宜用作镉污染土壤的修复。
A hydroponic experiment was conducted to investigate the cadmium (Cd) tolerance of and the Cd transportation and accumulation in Salix matsudana.S.matsudana showed a relatively higher tolerance to Cd.Its growth was promoted by Cd when Cd concentration in the medium was 0.2 mg·L-1.Phloem played an important role in the long distance Cd transportation from root to shoot.The top tissues of the plant had significantly higher Cd concentration (P0.05) than the bottom tissues,and phloem had 14 times higher Cd concentration than xylem.Shoot had strong sustainable capability in accumulating Cd.The accumulated Cd in aboveground part,especially in leaves,accounted for 52%-62% of the total.Consequently,through cleaning out the fallen leaves of S.matsudana during its defoliation stage,soil Cd could be removed.S.matsudana would be a suitable plant for the phytoremediation of Cd-polluted soil.